The objectives are to investigate age-related changes in access to long- standing knowledge and to establish the effect of cognitive aging on the half-life of interventions designed to stabilize access to knowledge. The research will yield normal information about the impact of cognitive aging on accessing available semantic memory content and on the effectiveness of interventions that re-establish access. The findings will differentiate normal from pathological cognitive again impairment. A further purpose is to extend current theories of cognitive aging so as to accommodate age-related changes of memory functioning that are largely independent of processing speed and of processing capacity. Participants in three age groups will be tested for recall and recognition of foreign language vocabulary acquired in school. The difficulty/frequency level of words assigned to the recall and recognition tests will be equated. The data will be subjected to multiple regression analyses. An evaluation of regression will yield predictions of recall access to vocabulary as a function of the age of the individual, the available vocabulary, the level of original knowledge, rehearsals of that knowledge, the retention interval, processing speed, and performance on acquisition of new vocabulary and the interactions among these variables. The half-life of corrective and of preventive maintenance interventions that re-establish or stabilize access to marginal memory targets will be evaluated as a function of the type of target (e.g., nouns, verbs, specific names), the age of the individual, and other individual difference variables and their interactions. The results will yield age-related guidelines regarding effective strategies for stabilizing access to available knowledge, and the results will be related to current theories of cognitive aging.